The projected need for Indian rhesus macaques for AIDS-related research continues to exceed availability. Given the increase in nonhuman primate use for AIDS-related opportunistic infection research, and their projected use for research focused on emerging disease and agents exploitable for bioterrorism, this shortage will likely continue for years to come. While source countries are a potentially important reserve of untapped production, the increasing difficulty of transporting nonhuman primates both internationally and domestically suggests relying on imports may provide only short term relief. Further, nonhuman primates with the level of genetic and microbial characterization prerequisite for many research models are currently not available from source country production resources. Domestic breeding programs managed to produce the well characterized animals necessary for cutting-edge research offer the best long-term solution for the current shortage of Indian-origin rhesus macaques for AIDS vaccine and pathogenesis studies. Investment in domestic breeding programs will also insure future availability. The comprehensive objective of this application is to increase the capacity of the ONPRC AIDS Research Expanded SPF Breeding Colony to provide genetically characterized Indian-origin rhesus macaques free of a broad number of enzootic and zoonotic agents to enhance the usefulness of the resource for cutting edge opportunistic agent and vaccine research. The specific aims for accomplishing this objective are to a) maintain and continue to expand the ONPRC AIDS Research Expanded SPF Rhesus Macaque Breeding Colony to a target population of 100adult breeder females capable of producing 35 surplus animals annually for research use, b) optimize the potential usefulness of rhesus macaques produced in the ONPRC AIDS Research Expanded SPF Breeding Colony for vaccine research by ensuring SPF status and managing the colony for the production of offspring of known parentage and genetic background that are MHC-defined, and c) improve infrastructure necessary to maintain the ONPRC AIDS Research Expanded SPF Rhesus Macaque Breeding Colony as a closed and protected resource.